External DAC with two analog outputs.

Maybe native instruments audio 6 will fit your needs. It has usb 24/96, but I don't know much about implementation. You are in the studio / dj territory if you want two exclusive rca outs. Maybe you can buy second hand dac with parallel xlr/rca outs and use xlr to rca cable but I think that it will be above your budget.

Do you want two stereo outputs each producing a different program,

 

i.e. cueing up the  next track or talking on Skype and listening to music at the same time?

 

or same program to speakers and headphones?

 

A secondary fun system, I think that NI Audio 6 will be good. And if you have a desktop pc maybe a cheap pci firewire card with Roland FA 66 or Presonus Firebox. Well I am in the same situation but I need xlr out for my primary system and rca for my living room causal set up. Violectric v800 is what I "need" all that is left is to save money and not spend it in between on something completely different:)

the closest I can think of is Audio-Gd NFB 3.2, but that is 300+. if you want stay below 200, why not considering using RCA splitter?

if you just need RCA try something like this with what you already have:

 

http://www.amazon.com/Wired-Up-PHONO-AUDIO-SPLITTER-ADAPTER/dp/B000L980MU/ref=sr_1_112?ie=UTF8&qid=1342052330&sr=8-112&keywords=2+1+rca+adapter

 

I use these:

 

http://www.amazon.com/AudioQuest-adapter-male-female-assembly/dp/B0009MFRW0/ref=sr_1_5?ie=UTF8&qid=1342052456&sr=8-5&keywords=2+1+rca+adapter+audioquest
 

Burson Audio DA-160 is one of them. 

 

You may also consider a headphone amp with fixed line level output. e.g. Creek OBH-11.

How about NFB-12.1, USD 215+shipping.

You can request to have 2x RCA output.

Splitting the RCA out lke this doesn't attenuate or otherwise degrade the signal? It must have some effect at some point, because you couldn't take one set of RCA puts and split it (say, for the case of an extreme example) 100 ways without any audible impact, right? Your RCA out 'driver' then has to drive multiple lines - I guess the question is how much headroom it has to split the signal without running out of juice. Just curious as this would be handy for me since I have multiple headphone amp options, but would hesitate if it degraded the SQ.

pretty inexpensive to try. Can it burn out the output device sending the signal? Is the signal conducting on both devices even though one is off? I'd think as long as only one device is used, there shouldn't be a problem. Otherwise they wouldn't have the market to sell it.

Focusrite Saffire 6 USB. I'm getting one for almost the exact same reasons you would be (Headphone out with seperate RCA [2 pairs] AND a TRS output [1/4 stereo output]). I'll be running my Mackie MR5 MK2's through the TRS outputs and then adding a tube amp later through the RCA outs. Because it Has 2 stereo RCA outputs and the TRS out you could run up to 3 amps out of it or  1 RCA to your home system, 1 pair of studio monitors (TRS), a desk headphone amp (through your other RCA set) AND a 1/4' out for your OTHER headphones. All this for the low low price of $200 USD....